This presentation is about affordance and their types...mapping and causality,convention and constraints..

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2. HCI
ASSIGNMENT
M U H A M M A D K A S H A N
U S M A N A H M A D
B A B A R A L I 2

3. OUTLINE
Affordance
Perceived Affordance
Real Affordance
Mapping
Causality
Constraints.
Conventions.
Conclusion
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4. AFFORDANCE
Affordance maens “What you can do with something”. (Neilsen/Budiu
)
An other definition of Affordance
“What the user CAN SEE that an OBJECT DOES”.
Affordance answers how do i use it?
• Giving a clue...!
• Example:
switch for toggling
chairs are for sitting
table for placing things on 4

5. TYPES OF AFFORDANCE
There are two types of affordance
 Perceived affordance.
 Real affordance.
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6. PERCEIVED AFFORDANCE
“The perceived properties of the object that suggest how one could use it”
OR
“Type of actions a user perceives to be possible”
Problems occur when
 These are not the same,
 People’s perceptions are not what the
designer expects
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7. PERCEIVED AFFORDANCE
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8. PERCEIVED AFFORDANCE
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9. REAL AFFORDANCE
• The actual actionable properties of the product
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10. REAL AFFORDANCE
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11. MAPPINGM
the relationship between control and their effect....
the natural relationship between controls and displays
e.g., when we preess the on button of swith then the light wiill be on...or off...
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12. MAPPING
Control-display compatibility
– cause and effect
steering wheel turn
left, car turns left
scroll bar – scroll
down
viewport goes down
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13. MAPPING PROBLEMS
Quick, open the top drawer
Mapping:
suggests it should open
the drawer but doesn’t
Affordance:
handle is for pulling
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14. CAUSALITY
the thing that happens right after an action is
assumed by people to be caused by that action
 interpretation of “feedback”
 false causality
• incorrect effect
– invoking unfamiliar function just as computer hangs
– causes “superstitious” behaviours
• invisible effect
– command with no apparent result often re-entered repeatedly
– e.g., mouse click to raise menu on unresponsive system
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15. CAUSALITY PROBLEMS
Effects visible only after Exec button is pressed
– Ok does nothing!
– awkward to find appropriate color level
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16. CONSTRAINTS
• The state of being checked, restricted, or compelled to avoid or perform some action.
• For the effective and efficient use of any application constraints are really necessary.
• There are certain types of constraints:
– Cultural constraints.
– Logical constraints.
– Physical constraints.
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17. CONSTRAINTS(LOGICAL)
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18. CONSTRAINTS(LOGICAL)
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19. CONSTRAINTS(LOGICAL)
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20. CONSTRAINTS(PHYSICAL)
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21. CONVENTIONS
• Conventions are actually cultural constraints.
• They can’t be change so easily.
• Designers must have to kept in mind and design according to the international
standards.
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22. CONVENTIONS(CALCULATOR)
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23. CONVENTIONS(FONT EFFECTS)
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24. CONVENTIONS(THE ATTACHMENT SYMBOL)
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25. CONCLUSION
• All steps are equally important.
• So all the steps must be considered while developing any application.
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26. THANK YOU !!!
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